Challenging the Conventional View of Gut Hormones as Primary Appetite Controllers | Research

The takeaway

In healthy individuals, gut peptide hormones (CCK, PYY, GLP-1) may play a smaller role in normal appetite regulation than traditionally believed, with hedonic and neurocognitive factors potentially being more important.

Largest endocrine system, uncertain appetite role
The enteroendocrine system may influence appetite more in disease than in health

What the researchers found

Postprandial gut peptide hormones may not play a dominant role in normal appetite regulation in healthy individuals; their impact may be more significant in GI disease states where levels become supraphysiological.

Why it matters

Billions of dollars are being invested in gut hormone-based therapies for obesity. Understanding the limitations of the gut hormone-appetite connection in healthy individuals may redirect research toward more effective targets.

The numbers in context

CCK, PYY, GLP-1 discussed; largest endocrine system; hedonic > hormonal in normal appetite; supraphysiological levels in disease

How the study worked

Narrative review of published evidence on enteroendocrine system function, gut peptide hormones, and appetite regulation in health and GI disease.

Who was studied

Review of enteroendocrine system function in healthy and diseased states

What this study cannot tell us

Narrative review presenting a perspective — not a systematic analysis. The alternative hypothesis (hedonic/cognitive dominance) is also not fully proven.

How to read the evidence

Narrative review presenting a provocative hypothesis. Raises important questions but doesn't provide definitive evidence for or against the proposed paradigm shift.

When this study was published

Published in 2021, offering a timely reassessment as GLP-1 agonists gain widespread use for weight management.

The bigger picture

The success of GLP-1 agonists for weight loss might seem to contradict this review, but the authors note that pharmacological doses far exceed natural postprandial levels. This distinction between physiological and pharmacological effects is crucial for understanding how these hormones work and for developing better obesity treatments.

Questions still open

If gut hormones don't primarily control appetite, why do GLP-1 drugs cause weight loss?
Could hedonic-targeted therapies be more effective for obesity than gut hormone manipulation?
Do gut peptides serve primarily as digestive regulators rather than appetite controllers?

Common questions

Do gut hormones really control how hungry you feel?

This review suggests they may not play as big a role as traditionally thought in healthy people. While gut hormones like GLP-1 and PYY rise after meals, the evidence that these natural levels actually control your appetite is weaker than commonly believed. Pleasure-seeking and psychological factors may matter more for normal eating.

If gut hormones don't control appetite, why do GLP-1 drugs help with weight loss?

The key is dose. GLP-1 drugs like semaglutide deliver far higher levels than the body produces naturally after a meal. At these pharmacological doses, appetite suppression is dramatic. But the natural postprandial levels of these hormones may not be the primary drivers of everyday appetite in healthy people.

Read the original research

Appetite, the enteroendocrine system, gastrointestinal disease and obesity.

The Proceedings of the Nutrition Society, 80(1), 50-58

View on PubMed ↗Publisher’s paper ↗

Citation

Crooks, Benjamin; Stamataki, Nikoleta S; McLaughlin, John T. (2021). Appetite, the enteroendocrine system, gastrointestinal disease and obesity.. The Proceedings of the Nutrition Society, 80(1), 50-58. https://doi.org/10.1017/S0029665120006965